Application of geological strength index for characterization of weathering-induced failures

Abstract

This study investigates weathering induced failures of the heterogeneous fissile rock mass consisting of sandstone and shale. Discontinuity data was collected and the geological strength index (GSI) value was determined immediately after excavation based on the quantified GSI chart. Slake durability tests were performed up to the fifth cycle. Samples were exposed to natural climatic conditions during a twelve-month period, in order to quantify slaking process by means of disintegration ratio. As a consequence of exposure, samples disintegrated into smaller fragments. On these bases, the model aimed at addressing delayed failure of cuts is proposed in the paper.